Update RSSManager.java

Fixed XML External Entity (XXE) Processing.
Check https://www.owasp.org/index.php/XML_External_Entity_%28XXE%29_Processing for more details on this

Author: smadappa

rss-middletier/src/main/java/com/netflix/recipes/rss/manager/RSSManager.java

@@ -147,6 +147,8 @@ private RSS parseRSS(String url, String rss) {
 
         RSS rssItems = null;
         DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
+        String FEATURE = "http://apache.org/xml/features/disallow-doctype-decl";
+        dbf.setFeature(FEATURE, true);        
         try {
             DocumentBuilder db = dbf.newDocumentBuilder();
             try {
@@ -183,4 +185,4 @@ private RSS parseRSS(String url, String rss) {
     public int getStatus() {
         return store == null ? 500 : 200;
     }
-}
+}